The Role of Vitamin C in the Treatment of the Common Cold
Dr Harri Hemila MD PhD co author of the Cochrane Review article replies :
The Cochrane review was limited to placebo-controlled trials in which at least 0.2 g of vitamin C was used per day. Most of these trials examined vitamin C administration as regular supplementation and provided strong evidence that vitamin C shortens the duration of colds and alleviates its symptoms. Children benefited more than adults. The data also suggested that high doses of vitamin C are more beneficial than low doses.[2-6]
Stratification of the regular supplementation trials in children by vitamin C dosage shows a tendency for dose dependency. Four trials, using 0.20 to 0.75 g of vitamin C per day, found an average reduction of 7 percent in common cold duration (95% confidence interval [CI], -19 to 5). Six trials with 1 g of vitamin C per day found an average reduction of 18 percent (95% CI, -32 to -3), and two trials using 2 g of vitamin C per day found an average reduction of 25 percent (95% CI, -50 to 0.1). Therefore, the 13.6 percent estimate for common cold reduction we calculated in the Cochrane review , based on all 12 trials with children who received at least 0.2 g of vitamin C per day, may underestimate the effect of high doses.
Extracted from a letter published in The American Academy of Family Physicians Oct 15th 2007 View letter
1. Simasek M, Blandino DA. Treatment of the common cold. Am Fam Physician 2007;75:515-20.
2. Douglas RM, Hemilä H, D’Souza R, Chalker EB, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2004;(4):CD000980.
3. Karlowski TR, Chalmers TC, Frenkel LD, Kapikian AZ, Lewis TL, Lynch JM. Ascorbic acid for the common cold. A prophylactic and therapeutic trial. JAMA 1975;231:1038-42.
4. Hemilä H. Vitamin C, the placebo effect, and the common cold: a case study of how preconceptions influence the analysis of results. J Clin Epidemiol 1996;49:1079-84.
5. Hemilä H. Vitamin C supplementation and common cold symptoms: factors affecting the magnitude of the benefit. Med Hypotheses 1999;52:171-8.
6. Hemilä H. Do vitamins C and E affect respiratory infections? [Academic Dissertation] University of Helsinki, Helsinki, Finland, January 2006:21-7, 36-45, 48-9, 62-3. Accessed August 6, 2007: view paper
8th October 2016
The role of the complex community of microbial dwellers inside our digestive tract remains a valuable, but still poorly understood resource in which changes to density and variety can have significant effects on human function and health. One of the roles of these organisms is in the generation of endogenous defence molecules including the master antioxidant, glutathione.Click for further information
30th March - 3rd April 2017
Applying Functional Medicine in Clinical Practice is a well-orchestrated, comprehensive, patient centered educational programme that helps you deepen your clinical understanding and practical application of the Functional Medicine Matrix ModelClick for further information
- Once you have your food selection sorted, exerc...
Dietary Fibre and Bacterial SCFA Enhance Oral Tolerance and Protect against Food Allergy through Diverse Cellular PathwaysIn June 2016 Cell Reports a well-respected scie...
- The American Addictions Centre have created a w...
- Antony Haynes BA(Hons) RNT undertakes a review ...
- Humic Acid This is a review of the anti-viral p...
Updates on your email
Don't miss out on our email updates